Enhanced control surgery (ECS) systems broadly refers to devices and systems that consist of mechanical or electromechanical configurations and that may provide one or more enhanced endo-mechanical features that enable a surgeon with improved surgical end effector mobility. Examples of such improvements include increased instrument flexibility, better ergonomic positioning, hand tremor reduction, translation of motion frames of reference, telesurgery, robotic surgery systems and the like. ECS systems typically include more elaborate instruments and support structures when compared to traditional laparoscopic surgery and may also include the use of novel body entry devices and different points of entry compared to laparoscopic or other minimally invasive surgical techniques.
Electrosurgical systems have utilized Active Electrode Monitoring (“AEM”) for several years, such as AEM monitor systems manufactured by Encision, Inc. of Boulder, Colo. These systems are generally described in U.S. Pat. No. 5,312,401 and related patents. Despite the success obtained, and increased patient safety realized, by the inventions embodied in the '401 patent, as well as the electrosurgical tools that embody those inventions, there remain certain problems and drawbacks when applied to ECS systems.
These drawbacks include, among other things, 1) the need to provide instrument shielding on structures that are not rigid shafts and that include complex articulating geometries found in ECS systems and tools, and 2) the need to monitor one or more non-electrosurgical instruments. As used herein, the term “cold instrument” refers to a surgical tool or device that does not have or is not meant to have electrosurgical energy actively applied to it or its end effector. These cold instruments can, under certain conditions, conduct electrical energy that can become harmful to the patient and cause burns. The same harmful conditions that can provide electrical energy to the cold instruments can also effect floating conductive surfaces that might also be in contact with the patient or operating room staff, such as the operating table or the mechanical support structure used to hold and control the ECS systems.
Current procedures used in minimally invasive electrosurgery utilize multiple access ports for the various instruments. Though devices such as the Encision AEM® monitoring system protect the active electrode instrument, the potential still exists that the surgeon might inadvertently or purposefully touch another instrument such as a grasper or optical scope with the active and electrically charged instrument. This additional instrument then has the potential to transfer electrical energy directly to the patient in an area that may not be visible to the surgeon. In addition, new surgical techniques involving single port access surgery (SPA), robotic surgery, and natural orifice transluminal endoscopy (NOTES) position the instruments in even closer proximity to each other and contain more non-referenced conductive surfaces that can inadvertently carry electrical energy. While SPA apparatus (instruments and cannulae) are generally not used for ECS systems as described above, they involve different points of entry compared to traditional laparoscopic surgery. For instance, SPA surgery might be used for cosmetic reasons, reduced pain, and reduced chance for herniation. Because all instruments pass through a single incision (e.g. the umbilicus) they are very close together and increase the likelihood of cross-coupling of energy compared to traditional laparoscopic surgery. This highlights the need for both active instrument protection and for cold instrument monitoring and protection.
Thus, there is a need for a better way to provide a monitored electrosurgical energy to the primary “hot” instrument while also monitoring for inadvertent stray electrosurgical energy in cold instruments and other conductive surfaces. In addition, because of the added degrees of freedom and the need to accommodate advanced monitoring techniques in the more complex and larger scale instruments being utilized in ECS surgical techniques, prior monitoring techniques used in rigid shaft embodiments are not adequate.